Braking apparatus

Abstract

A brake apparatus is disclosed in which a rotary shaft coupled to a load to be rotated is rotatably supported by a plain bearing and a biasing device is located near the shaft to bias or move the shaft to the biasing device to applying braking force to the rotating load by the friction between the shaft and its bearing so as to stop the rotation of shaft and hence load.

We claim as our invention: 
     
       1. A brake apparatus for rotating body comprising: a. bearing means for rotatably supporting a rotary shaft to which a load to be rotated is fixed; and   b. biasing means located near said shaft for biasing said shaft in the direction to said bearing means to cause frictional force between said shaft and bearing means so as to brake said load.   
     
     
       2. A brake apparatus as claimed in claim 1, in which said rotary shaft is a rotating shaft of an AC motor and said biasing means is a stator winding of said AC motor. 
     
     
       3. A brake apparatus as claimed in claim 1, in which said rotary shaft is a rotating shaft of an AC motor and an auxiliary winding of said AC motor is said biasing means. 
     
     
       4. A brake apparatus as claimed in claim 1, in which said rotary shaft is a rotating shaft of an AC motor and said biasing means is disposed in opposed relation to a rotor of said AC motor. 
     
     
       5. A brake apparatus according to claim 1 further comprising means for supplying DC current to said biasing means so as to magnetize said biasing means. 
     
     
       6. A brake apparatus as claimed in claim 5, in which said DC current supplying means is a DC current source. 
     
     
       7. A brake apparatus according to claim 1 further comprising means for supplying a pulse signal to said biasing means, said pulse signal being integrated by inductance components of said biasing means to be a DC signal. 
     
     
       8. A brake apparatus according to claim 1 further comprising means for detecting a rotation speed of said load and means supplied with an output of said detecting means for automatically selecting a signal supplied to said biasing means.